The present disclosure relates to an imaging apparatus and an image sensor array, and more particularly, to an imaging apparatus that images a subject as a stereo image, and to an image sensor array used in such an imaging apparatus.
For some time, various imaging apparatus have been proposed and developed. Additionally, there have been proposed imaging apparatus configured to perform given image processing on an imaging signal obtained by imaging and output the result, such as an imaging apparatus that images a subject as a stereo image, for example. For example, International Publication No. 06/039486 proposes an imaging apparatus that uses a technique called light field photography. The imaging apparatus includes an imaging lens, a microlens array (light field lens), a photosensitive element, and an image processor. An imaging signal obtained from the photosensitive element includes information on the light intensity at the photosensitive surface of the photosensitive element, as well as information on the travel direction of that light. Additionally, on the basis of such an imaging signal, an observed image from an arbitrary viewpoint or direction may be reconstructed in the image processor to obtain a stereo image.
Alternatively, there has been proposed a system in which a common subject is simultaneously imaged by two video cameras disposed to the left and right of each other, and a stereo image is displayed by simultaneously outputting the two images thus obtained (a right-eye image and a left-eye image). However, when two video cameras are used in this way, the apparatus becomes bulky and is impractical. Moreover, the baseline between the two video cameras, or in other words, the interpupillary distance of the stereo camera, is often set to approximately 65 mm, equivalent to the distance between the human eyes, irrespective of the lens zoom ratio. In such cases, binocular parallax increases for close-up images and forces the viewer's visual system to process information differently from daily life, which can lead to eyestrain. Additionally, imaging a moving subject with two video cameras involves precise synchronization control of the two video cameras and is extremely difficult. Accurate control of the angle of convergence is also extremely difficult.
In order to make adjusting the lens system easier for stereo photography, there has been proposed a stereo photography apparatus that uses a shared optical system by introducing a polarization filter which polarizes incoming light such that respective rays become orthogonal to each other (see Japanese Examined Patent Application Publication No. H6-054991, for example).
Also proposed is a technique that conducts stereo photography with an imaging apparatus made up of two lenses and one imaging means (see Japanese Unexamined Patent Application Publication No. 2004-309868, for example). The imaging apparatus disclosed in this patent application publication is provided with
imaging means in which a number of pixels corresponding to an integer multiple of a given number of scanlines are provided on an imaging surface,
first horizontal component polarizing means that transmits only horizontal components in first image light from a subject, and
first vertical component polarizing means, disposed separated from the first horizontal component polarizing means by a given distance, that transmits only vertical components in second image light from the subject,
wherein the horizontal components transmitted by the first horizontal component polarizing means are condensed onto a given range of pixels on the imaging surface, and
the vertical components transmitted by the first vertical component polarizing means are condensed onto a remaining range of pixels that excludes the given range. Specifically, a horizontal component polarizing filter and a vertical component polarizing filter are disposed separated by an interval corresponding to the parallax of the human eyes, and provided together with two lenses at a position separated from the imaging surface of a CCD by a given distance.